/*
** $Id: lopcodes.h $
** Opcodes for Lua virtual machine
** See Copyright Notice in lua.h
*/

#ifndef lopcodes_h
#define lopcodes_h

#include "llimits.h"


/*===========================================================================
  We assume that instructions are unsigned 32-bit integers.
  All instructions have an opcode in the first 7 bits.
  Instructions can have the following formats:

        3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0
        1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0
iABC          C(8)     |      B(8)     |k|     A(8)      |   Op(7)     |
iABx                Bx(17)               |     A(8)      |   Op(7)     |
iAsBx              sBx (signed)(17)      |     A(8)      |   Op(7)     |
iAx                           Ax(25)                     |   Op(7)     |
isJ                           sJ(25)                     |   Op(7)     |

  A signed argument is represented in excess K: the represented value is
  the written unsigned value minus K, where K is half the maximum for the
  corresponding unsigned argument.
===========================================================================*/


enum OpMode {iABC, iABx, iAsBx, iAx, isJ};  /* basic instruction formats */


/*
** size and position of opcode arguments.
*/
#define SIZE_C  8
#define SIZE_B  8
#define SIZE_Bx  (SIZE_C + SIZE_B + 1)
#define SIZE_A  8
#define SIZE_Ax  (SIZE_Bx + SIZE_A)
#define SIZE_sJ  (SIZE_Bx + SIZE_A)

#define SIZE_OP  7

#define POS_OP  0

#define POS_A  (POS_OP + SIZE_OP)
#define POS_k  (POS_A + SIZE_A)
#define POS_B  (POS_k + 1)
#define POS_C  (POS_B + SIZE_B)

#define POS_Bx  POS_k

#define POS_Ax  POS_A

#define POS_sJ  POS_A


/*
** limits for opcode arguments.
** we use (signed) 'int' to manipulate most arguments,
** so they must fit in ints.
*/

/* Check whether type 'int' has at least 'b' bits ('b' < 32) */
#define L_INTHASBITS(b)  ((UINT_MAX >> ((b) - 1)) >= 1)


#if L_INTHASBITS(SIZE_Bx)
#define MAXARG_Bx ((1<<SIZE_Bx)-1)
#else
#define MAXARG_Bx MAX_INT
#endif

#define OFFSET_sBx (MAXARG_Bx>>1)         /* 'sBx' is signed */


#if L_INTHASBITS(SIZE_Ax)
#define MAXARG_Ax ((1<<SIZE_Ax)-1)
#else
#define MAXARG_Ax MAX_INT
#endif

#if L_INTHASBITS(SIZE_sJ)
#define MAXARG_sJ ((1 << SIZE_sJ) - 1)
#else
#define MAXARG_sJ MAX_INT
#endif

#define OFFSET_sJ (MAXARG_sJ >> 1)


#define MAXARG_A ((1<<SIZE_A)-1)
#define MAXARG_B ((1<<SIZE_B)-1)
#define MAXARG_C ((1<<SIZE_C)-1)
#define OFFSET_sC (MAXARG_C >> 1)

#define int2sC(i) ((i) + OFFSET_sC)
#define sC2int(i) ((i) - OFFSET_sC)


/* creates a mask with 'n' 1 bits at position 'p' */
#define MASK1(n,p) ((~((~(Instruction)0)<<(n)))<<(p))

/* creates a mask with 'n' 0 bits at position 'p' */
#define MASK0(n,p) (~MASK1(n,p))

/*
** the following macros help to manipulate instructions
*/

#define GET_OPCODE(i) (cast(OpCode, ((i)>>POS_OP) & MASK1(SIZE_OP,0)))
#define SET_OPCODE(i,o) ((i) = (((i)&MASK0(SIZE_OP,POS_OP)) | \
  ((cast(Instruction, o)<<POS_OP)&MASK1(SIZE_OP,POS_OP))))

#define checkopm(i,m) (getOpMode(GET_OPCODE(i)) == m)


#define getarg(i,pos,size) (cast_int(((i)>>(pos)) & MASK1(size,0)))
#define setarg(i,v,pos,size) ((i) = (((i)&MASK0(size,pos)) | \
                ((cast(Instruction, v)<<pos)&MASK1(size,pos))))

#define GETARG_A(i) getarg(i, POS_A, SIZE_A)
#define SETARG_A(i,v) setarg(i, v, POS_A, SIZE_A)

#define GETARG_B(i) check_exp(checkopm(i, iABC), getarg(i, POS_B, SIZE_B))
#define GETARG_sB(i) sC2int(GETARG_B(i))
#define SETARG_B(i,v) setarg(i, v, POS_B, SIZE_B)

#define GETARG_C(i) check_exp(checkopm(i, iABC), getarg(i, POS_C, SIZE_C))
#define GETARG_sC(i) sC2int(GETARG_C(i))
#define SETARG_C(i,v) setarg(i, v, POS_C, SIZE_C)

#define TESTARG_k(i) check_exp(checkopm(i, iABC), (cast_int(((i) & (1u << POS_k)))))
#define GETARG_k(i) check_exp(checkopm(i, iABC), getarg(i, POS_k, 1))
#define SETARG_k(i,v) setarg(i, v, POS_k, 1)

#define GETARG_Bx(i) check_exp(checkopm(i, iABx), getarg(i, POS_Bx, SIZE_Bx))
#define SETARG_Bx(i,v) setarg(i, v, POS_Bx, SIZE_Bx)

#define GETARG_Ax(i) check_exp(checkopm(i, iAx), getarg(i, POS_Ax, SIZE_Ax))
#define SETARG_Ax(i,v) setarg(i, v, POS_Ax, SIZE_Ax)

#define GETARG_sBx(i)  \
 check_exp(checkopm(i, iAsBx), getarg(i, POS_Bx, SIZE_Bx) - OFFSET_sBx)
#define SETARG_sBx(i,b) SETARG_Bx((i),cast_uint((b)+OFFSET_sBx))

#define GETARG_sJ(i)  \
 check_exp(checkopm(i, isJ), getarg(i, POS_sJ, SIZE_sJ) - OFFSET_sJ)
#define SETARG_sJ(i,j) \
 setarg(i, cast_uint((j)+OFFSET_sJ), POS_sJ, SIZE_sJ)


#define CREATE_ABCk(o,a,b,c,k) ((cast(Instruction, o)<<POS_OP) \
   | (cast(Instruction, a)<<POS_A) \
   | (cast(Instruction, b)<<POS_B) \
   | (cast(Instruction, c)<<POS_C) \
   | (cast(Instruction, k)<<POS_k))

#define CREATE_ABx(o,a,bc) ((cast(Instruction, o)<<POS_OP) \
   | (cast(Instruction, a)<<POS_A) \
   | (cast(Instruction, bc)<<POS_Bx))

#define CREATE_Ax(o,a)  ((cast(Instruction, o)<<POS_OP) \
   | (cast(Instruction, a)<<POS_Ax))

#define CREATE_sJ(o,j,k) ((cast(Instruction, o) << POS_OP) \
   | (cast(Instruction, j) << POS_sJ) \
   | (cast(Instruction, k) << POS_k))


#if !defined(MAXINDEXRK)  /* (for debugging only) */
#define MAXINDEXRK MAXARG_B
#endif


/*
** invalid register that fits in 8 bits
*/
#define NO_REG  MAXARG_A


/*
** R[x] - register
** K[x] - constant (in constant table)
** RK(x) == if k(i) then K[x] else R[x]
*/


/*
** grep "ORDER OP" if you change these enums
*/

typedef enum {
    /*----------------------------------------------------------------------
      name  args description
    ------------------------------------------------------------------------*/
    OP_MOVE,/* A B R[A] := R[B]     */
    OP_LOADI,/* A sBx R[A] := sBx     */
    OP_LOADF,/* A sBx R[A] := (lua_Number)sBx    */
    OP_LOADK,/* A Bx R[A] := K[Bx]     */
    OP_LOADKX,/* A R[A] := K[extra arg]    */
    OP_LOADFALSE,/* A R[A] := false     */
    OP_LFALSESKIP,/*A R[A] := false; pc++    */
    OP_LOADTRUE,/* A R[A] := true     */
    OP_LOADNIL,/* A B R[A], R[A+1], ..., R[A+B] := nil  */
    OP_GETUPVAL,/* A B R[A] := UpValue[B]    */
    OP_SETUPVAL,/* A B UpValue[B] := R[A]    */

    OP_GETTABUP,/* A B C R[A] := UpValue[B][K[C]:string]   */
    OP_GETTABLE,/* A B C R[A] := R[B][R[C]]    */
    OP_GETI,/* A B C R[A] := R[B][C]     */
    OP_GETFIELD,/* A B C R[A] := R[B][K[C]:string]   */

    OP_SETTABUP,/* A B C UpValue[A][K[B]:string] := RK(C)  */
    OP_SETTABLE,/* A B C R[A][R[B]] := RK(C)    */
    OP_SETI,/* A B C R[A][B] := RK(C)    */
    OP_SETFIELD,/* A B C R[A][K[B]:string] := RK(C)   */

    OP_NEWTABLE,/* A B C k R[A] := {}     */

    OP_SELF,/* A B C R[A+1] := R[B]; R[A] := R[B][RK(C):string] */

    OP_ADDI,/* A B sC R[A] := R[B] + sC    */

    OP_ADDK,/* A B C R[A] := R[B] + K[C]    */
    OP_SUBK,/* A B C R[A] := R[B] - K[C]    */
    OP_MULK,/* A B C R[A] := R[B] * K[C]    */
    OP_MODK,/* A B C R[A] := R[B] % K[C]    */
    OP_POWK,/* A B C R[A] := R[B] ^ K[C]    */
    OP_DIVK,/* A B C R[A] := R[B] / K[C]    */
    OP_IDIVK,/* A B C R[A] := R[B] // K[C]    */

    OP_BANDK,/* A B C R[A] := R[B] & K[C]:integer   */
    OP_BORK,/* A B C R[A] := R[B] | K[C]:integer   */
    OP_BXORK,/* A B C R[A] := R[B] ~ K[C]:integer   */

    OP_SHRI,/* A B sC R[A] := R[B] >> sC    */
    OP_SHLI,/* A B sC R[A] := sC << R[B]    */

    OP_ADD,/* A B C R[A] := R[B] + R[C]    */
    OP_SUB,/* A B C R[A] := R[B] - R[C]    */
    OP_MUL,/* A B C R[A] := R[B] * R[C]    */
    OP_MOD,/* A B C R[A] := R[B] % R[C]    */
    OP_POW,/* A B C R[A] := R[B] ^ R[C]    */
    OP_DIV,/* A B C R[A] := R[B] / R[C]    */
    OP_IDIV,/* A B C R[A] := R[B] // R[C]    */

    OP_BAND,/* A B C R[A] := R[B] & R[C]    */
    OP_BOR,/* A B C R[A] := R[B] | R[C]    */
    OP_BXOR,/* A B C R[A] := R[B] ~ R[C]    */
    OP_SHL,/* A B C R[A] := R[B] << R[C]    */
    OP_SHR,/* A B C R[A] := R[B] >> R[C]    */

    OP_MMBIN,/* A B C call C metamethod over R[A] and R[B]  */
    OP_MMBINI,/* A sB C k call C metamethod over R[A] and sB */
    OP_MMBINK,/* A B C k  call C metamethod over R[A] and K[B] */

    OP_UNM,/* A B R[A] := -R[B]     */
    OP_BNOT,/* A B R[A] := ~R[B]     */
    OP_NOT,/* A B R[A] := not R[B]    */
    OP_LEN,/* A B R[A] := #R[B] (length operator)   */

    OP_CONCAT,/* A B R[A] := R[A].. ... ..R[A + B - 1]  */

    OP_CLOSE,/* A close all upvalues >= R[A]   */
    OP_TBC,/* A mark variable A "to be closed"   */
    OP_JMP,/* sJ pc += sJ     */
    OP_EQ,/* A B k if ((R[A] == R[B]) ~= k) then pc++  */
    OP_LT,/* A B k if ((R[A] <  R[B]) ~= k) then pc++  */
    OP_LE,/* A B k if ((R[A] <= R[B]) ~= k) then pc++  */

    OP_EQK,/* A B k if ((R[A] == K[B]) ~= k) then pc++  */
    OP_EQI,/* A sB k if ((R[A] == sB) ~= k) then pc++  */
    OP_LTI,/* A sB k if ((R[A] < sB) ~= k) then pc++   */
    OP_LEI,/* A sB k if ((R[A] <= sB) ~= k) then pc++  */
    OP_GTI,/* A sB k if ((R[A] > sB) ~= k) then pc++   */
    OP_GEI,/* A sB k if ((R[A] >= sB) ~= k) then pc++  */

    OP_TEST,/* A k if (not R[A] == k) then pc++   */
    OP_TESTSET,/* A B k if (not R[B] == k) then pc++ else R[A] := R[B] */

    OP_CALL,/* A B C R[A], ... ,R[A+C-2] := R[A](R[A+1], ... ,R[A+B-1]) */
    OP_TAILCALL,/* A B C k return R[A](R[A+1], ... ,R[A+B-1])  */

    OP_RETURN,/* A B C k return R[A], ... ,R[A+B-2] (see note) */
    OP_RETURN0,/*  return      */
    OP_RETURN1,/* A return R[A]     */

    OP_FORLOOP,/* A Bx update counters; if loop continues then pc-=Bx; */
    OP_FORPREP,/* A Bx <check values and prepare counters>;
                        if not to run then pc+=Bx+1;   */

    OP_TFORPREP,/* A Bx create upvalue for R[A + 3]; pc+=Bx  */
    OP_TFORCALL,/* A C R[A+4], ... ,R[A+3+C] := R[A](R[A+1], R[A+2]); */
    OP_TFORLOOP,/* A Bx if R[A+2] ~= nil then { R[A]=R[A+2]; pc -= Bx } */

    OP_SETLIST,/* A B C k R[A][C+i] := R[A+i], 1 <= i <= B  */

    OP_CLOSURE,/* A Bx R[A] := closure(KPROTO[Bx])   */

    OP_VARARG,/* A C R[A], R[A+1], ..., R[A+C-2] = vararg  */

    OP_VARARGPREP,/*A (adjust vararg parameters)   */

    OP_EXTRAARG/* Ax extra (larger) argument for previous opcode */
} OpCode;


#define NUM_OPCODES ((int)(OP_EXTRAARG) + 1)



/*===========================================================================
  Notes:
  (*) In OP_CALL, if (B == 0) then B = top - A. If (C == 0), then
  'top' is set to last_result+1, so next open instruction (OP_CALL,
  OP_RETURN*, OP_SETLIST) may use 'top'.

  (*) In OP_VARARG, if (C == 0) then use actual number of varargs and
  set top (like in OP_CALL with C == 0).

  (*) In OP_RETURN, if (B == 0) then return up to 'top'.

  (*) In OP_LOADKX and OP_NEWTABLE, the next instruction is always
  OP_EXTRAARG.

  (*) In OP_SETLIST, if (B == 0) then real B = 'top'; if k, then
  real C = EXTRAARG _ C (the bits of EXTRAARG concatenated with the
  bits of C).

  (*) In OP_NEWTABLE, B is log2 of the hash size (which is always a
  power of 2) plus 1, or zero for size zero. If not k, the array size
  is C. Otherwise, the array size is EXTRAARG _ C.

  (*) For comparisons, k specifies what condition the test should accept
  (true or false).

  (*) In OP_MMBINI/OP_MMBINK, k means the arguments were flipped
   (the constant is the first operand).

  (*) All 'skips' (pc++) assume that next instruction is a jump.

  (*) In instructions OP_RETURN/OP_TAILCALL, 'k' specifies that the
  function builds upvalues, which may need to be closed. C > 0 means
  the function is vararg, so that its 'func' must be corrected before
  returning; in this case, (C - 1) is its number of fixed parameters.

  (*) In comparisons with an immediate operand, C signals whether the
  original operand was a float. (It must be corrected in case of
  metamethods.)

===========================================================================*/


/*
** masks for instruction properties. The format is:
** bits 0-2: op mode
** bit 3: instruction set register A
** bit 4: operator is a test (next instruction must be a jump)
** bit 5: instruction uses 'L->top' set by previous instruction (when B == 0)
** bit 6: instruction sets 'L->top' for next instruction (when C == 0)
** bit 7: instruction is an MM instruction (call a metamethod)
*/

LUAI_DDEC(const lu_byte luaP_opmodes[NUM_OPCODES];)

#define getOpMode(m) (cast(enum OpMode, luaP_opmodes[m] & 7))
#define testAMode(m) (luaP_opmodes[m] & (1 << 3))
#define testTMode(m) (luaP_opmodes[m] & (1 << 4))
#define testITMode(m) (luaP_opmodes[m] & (1 << 5))
#define testOTMode(m) (luaP_opmodes[m] & (1 << 6))
#define testMMMode(m) (luaP_opmodes[m] & (1 << 7))

/* "out top" (set top for next instruction) */
#define isOT(i)  \
 ((testOTMode(GET_OPCODE(i)) && GETARG_C(i) == 0) || \
          GET_OPCODE(i) == OP_TAILCALL)

/* "in top" (uses top from previous instruction) */
#define isIT(i)  (testITMode(GET_OPCODE(i)) && GETARG_B(i) == 0)

#define opmode(mm,ot,it,t,a,m)  \
    (((mm) << 7) | ((ot) << 6) | ((it) << 5) | ((t) << 4) | ((a) << 3) | (m))


/* number of list items to accumulate before a SETLIST instruction */
#define LFIELDS_PER_FLUSH 50

#endif
